"Victoria saw a 33 per cent increase in solar connections for the first six months of 2012 compared to the same period in 2011, despite the feed-in tariff stepping down from 60c/kWh to 25c/kWh," Mr O'Brien says.

"This demonstrates that it is the falling cost of solar and the rising price of electricity that is driving uptake, rather than feed-in tariffs."

The feed-in tariff of eight cents applies from 1 January 2013.

Solar customers who currently get a premium feed-in tariff or the transitional feed-in tariff will not be affected and conclusion dates for both of those schemes will not change.

People who have already paid a deposit or are just getting their system installed may still be considered for the higher transitional rate if their paperwork is lodged by the end of this month.